This invention relates to blind fasteners and more particularly to a blind fastener of the type that can be installed entirely from one side of a structure and has an insert threaded portion that cooperates with the main body of the fastener to provide a floating action to compensate for misalignment of Parts to be interconnected. Conventional blind fasteners have an internal screw thread that facilitates the upsetting action of a tubular body of the fastener, which upsetting action cooperates with the head of the fastener to secure the fastener in its position on the structure or plate members. It was important in these installations to locate the hole within the structure that receives the blind fastener precisely as any deviation from the intended installation hole would result in the need to provide either another hole for a second fastener or else adjust the product or member that was to be installed on the structure. The present invention provides a new and improved means for compensating for misalignment by having a threaded sleeve that is loosely journaled within the lower portion of the tubular portion of the fastener, which tubular portion is upset thereby securely locking the fastener in position on the structure while providing versatility to the fastener. With the loosely fitting threaded sleeve, sufficient clearance is obtainable in all directions to compensate for any slight misalignment of the fastener body thus increasing efficiency and versatility. The present construction is a material improvement over a self-aligning nut assembly such as illustrated by U.S. Pat. No. 2,553,236 since nut element with its short axial length contributes to false starts of the screw threads and the stripping thereof which renders the fastener useless as well as requiring the removal thereof. In addition, locking threads are often used in the fastener elements in the aircraft industry whereas the threaded element of the present invention provides non-locking threads that act as a guide so that the male threaded element may be easily engaged in the lower locking threads. The present invention is less costly to manufacture and permits the use of different size sleeves which can be assembled at the place of use prior to installation. With these combination of elements there is provided a fastener that is smaller for a given thread size than heretofore possible. In addition, the fastener, particularly the threaded sleeve, is easy to manufacture using techniques well known in the art. The shear strength of the fastener may be increased by the use of a shoulder bolt or a spacer to fill the counterbore area.
These type of fasteners are particularly useful in the aircraft industry where lightweight blind type fasteners are necessary.